Problem: On the way to school, Karen became fixated on the puzzle game on her phone!

<image>

The game is played as follows. In each level, you have a grid with n rows and m columns. Each cell originally contains the number 0.

One move consists of choosing one row or column, and adding 1 to all of the cells in that row or column.

To win the level, after all the moves, the number in the cell at the i-th row and j-th column should be equal to gi, j.

Karen is stuck on one level, and wants to know a way to beat this level using the minimum number of moves. Please, help her with this task!

Input

The first line of input contains two integers, n and m (1 ≤ n, m ≤ 100), the number of rows and the number of columns in the grid, respectively.

The next n lines each contain m integers. In particular, the j-th integer in the i-th of these rows contains gi, j (0 ≤ gi, j ≤ 500).

Output

If there is an error and it is actually not possible to beat the level, output a single integer -1.

Otherwise, on the first line, output a single integer k, the minimum number of moves necessary to beat the level.

The next k lines should each contain one of the following, describing the moves in the order they must be done:

  * row x, (1 ≤ x ≤ n) describing a move of the form "choose the x-th row". 
  * col x, (1 ≤ x ≤ m) describing a move of the form "choose the x-th column". 



If there are multiple optimal solutions, output any one of them.

Examples

Input

3 5
2 2 2 3 2
0 0 0 1 0
1 1 1 2 1


Output

4
row 1
row 1
col 4
row 3


Input

3 3
0 0 0
0 1 0
0 0 0


Output

-1


Input

3 3
1 1 1
1 1 1
1 1 1


Output

3
row 1
row 2
row 3

Note

In the first test case, Karen has a grid with 3 rows and 5 columns. She can perform the following 4 moves to beat the level:

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In the second test case, Karen has a grid with 3 rows and 3 columns. It is clear that it is impossible to beat the level; performing any move will create three 1s on the grid, but it is required to only have one 1 in the center.

In the third test case, Karen has a grid with 3 rows and 3 columns. She can perform the following 3 moves to beat the level:

<image>

Note that this is not the only solution; another solution, among others, is col 1, col 2, col 3.

Solution (in JAVA):

Solution:
import java.io.OutputStream;
import java.io.IOException;
import java.io.InputStream;
import java.io.PrintWriter;
import java.io.PrintStream;
import java.io.BufferedInputStream;
import java.util.InputMismatchException;
import java.io.IOException;
import java.io.InputStream;

/**
 * Built using CHelper plug-in
 * Actual solution is at the top
 */
public class Main {
	public static void main(String[] args) {
		InputStream inputStream = System.in;
		OutputStream outputStream = System.out;
		BufferedInputStream in = new BufferedInputStream(inputStream);
		PrintWriter out = new PrintWriter(outputStream);
		TaskC solver = new TaskC();
		solver.solve(1, in, out);
		out.close();
	}

	static class TaskC {
		int[][] temp;
		int n;
		int m;
		int[] br;
		int[] bc;

		int ok(int[] c, int[][] g) {
			for (int i = 0; i < n; ++i)
				for (int j = 0; j < m; ++j) {
					temp[i][j] = g[i][j] - c[j];
					if (temp[i][j] < 0) return -1;
				}

			int re = 0;


			for (int i = 0; i < n; ++i) {
				int t0 = temp[i][0];
				for (int j = 0; j < m; ++j) {
					if (temp[i][j] != t0) return -1;

				}
				re += t0;
				br[i] = t0;
			}

			for (int i = 0; i < m; ++i) re += c[i];

			return re;
		}

		public void solve(int testNumber, BufferedInputStream _in, PrintWriter out) {
			InputReader in = new InputReader(_in);
			long startTime = System.currentTimeMillis();
			n = in.nextInt();
			m = in.nextInt();
			br = new int[n];
			bc = new int[m];
			int[][] g = new int[n][m];
			temp = new int[n][m];

			int[] c = new int[m];

			for (int i = 0; i < n; ++i)
				for (int j = 0; j < m; ++j) g[i][j] = in.nextInt();


			int minr0 = g[0][MathUtils.min(g[0])];

			int best = Integer.MAX_VALUE;
			for (int r0 = 0; r0 <= minr0; ++r0) {
				for (int i = 0; i < m; ++i) c[i] = g[0][i] - r0;
				int tt = ok(c, g);
				if (tt != -1) {
					if (tt < best) {
						best = tt;
						for (int i = 0; i < m; ++i) bc[i] = c[i];
					}
				}
			}

			if (best == Integer.MAX_VALUE) {
				out.print(-1);
			} else {
				out.println(best);
				ok(bc, g);
				for (int i = 0; i < n; ++i) {
					for (int j = 0; j < br[i]; ++j) {
						out.println("row " + (i + 1));
					}
				}

				for (int i = 0; i < m; ++i) {
					for (int j = 0; j < bc[i]; ++j) {
						out.println("col " + (i + 1));
					}
				}
			}

			in.close();
			System.err.println("Time: " + (System.currentTimeMillis() - startTime) + " miliseconds");
		}

	}

	static class MathUtils {
		public static int min(int[] a) {
			if (a.length == 0)
				throw new RuntimeException();

			int ret = a[0];
			int save = 0;

			for (int i = 1; i < a.length; ++i)
				if (a[i] < ret) {
					ret = a[i];
					save = i;
				}

			return save;
		}

	}

	static class InputReader {
		private InputStream stream;
		private byte[] buf = new byte[1024];
		private int curChar;
		private int numChars;

		public InputReader(InputStream stream) {
			this.stream = stream;
		}

		public int read() {
			if (numChars == -1)
				throw new InputMismatchException();
			if (curChar >= numChars) {
				curChar = 0;
				try {
					numChars = stream.read(buf);
				} catch (IOException e) {
					throw new InputMismatchException();
				}
				if (numChars <= 0)
					return -1;
			}
			return buf[curChar++];
		}

		public int nextInt() {
			int c = read();
			while (isSpaceChar(c))
				c = read();
			int sgn = 1;
			if (c == '-') {
				sgn = -1;
				c = read();
			}
			int res = 0;
			do {
				if (c < '0' || c > '9')
					throw new InputMismatchException();
				res *= 10;
				res += c - '0';
				c = read();
			} while (!isSpaceChar(c));
			return res * sgn;
		}

		public static boolean isSpaceChar(int c) {
			return c == ' ' || c == '\n' || c == '\r' || c == '\t' || c == -1;
		}

		public void close() {

		}

	}
}